Muneya Kato is puzzled. He adjusts his glasses, then nervously threads and unthreads his fingers. A dapper-looking man in his early 50s, he looks more like a bank executive than the editor-in-chief of Mitabungkaku, one of Japan's most distinguished literary magazines.

"But why?" he asks again. He pauses and smiles quickly, as though to reassure me that he does not mean to be rude or intrusive. And then he changes tack. "Endo Shusaku" - he uses the traditional Japanese way of placing the family name first - "he would have enjoyed today. I am sorry he is not able to meet you."

I too am sorry, but meeting Muneya Kato is the next best thing. All enquiries about the late Mr Endo have been met with the "news" that I should speak with Mr Muneya Kato. And now we are seated together in the coffee lounge of a large hotel in the Shibuya district of central Tokyo.

Mr Kato's question still hangs in the air. Why, he wants to know, does a Caribbean-born British writer consider Shusaku Endo to be a great personal influence upon his own work? The truth is I have travelled all the way to Japan, in part, to seek out an answer to this very question. I have already told Mr Kato that the gentle intimacy of Endo's narrative style, with his deeply reflective first-person voices, has always appealed to me. Despite the intrusive "barrier" of translation, Endo's novels have always provided me with valuable instruction in how to locate character.

Understandably, this technical and somewhat convoluted explanation of my connection to Endo has failed to satisfy Mr Kato. He continues to look at me with a puzzled expression. Mr Kato is still trying to understand how I have made a personal connection across race, nationality, religion and generation with his "master", the man to whom he has dedicated the greater part of his life. As the waitress places two more cups of coffee in front of us I am beginning to flush with embarrassment, unsure if I can help him.

Shusaku Endo was born in Tokyo in 1923. He spent his early years in Manchuria, but after the separation of his parents he and his mother returned to Japan and moved in with an aunt who persuaded Endo's mother to convert to Catholicism. Soon after, the mother convinced her young son to be baptised and Endo found himself part of the tiny minority group of Catholics in Japan. The religion did not sit easily on Endo's shoulders, and his shallow commitment caused him to suffer great feelings of guilt, for he felt sure that he was disappointing his mother. In 1950, Endo became the first Japanese student after the second world war to leave the country and study abroad. He travelled to France, where he enrolled in the University of Lyon in order that he might pursue his burgeoning interest in 20th-century Catholic fiction.

These two events, the thrusting upon him of Catholicism, and his being exposed to the world beyond Japan, created a peculiar prism through which Endo peered upon Japanese society. When the young author returned home to Japan, and began to embark upon his career as a writer, he was immediately fascinated by questions of guilt and responsibility in Japanese society and history.

These questions were all the more problematic for him because he continued to find himself uncomfortable with certain aspects of his faith. His first great book, The Sea and Poison (1958), concerns the illegal vivisection of American soldiers by Japanese doctors during the second world war, and it is based on historical fact. The lack of conscience of the doctors is set against the agonising predicament of a young intern, Dr Suguro, who feels compelled to obey orders despite his harbouring profound reservations about the actions of his superiors.

The novel Silence (1966), which most critics consider to be Endo's masterpiece, is an austere historical drama which deals more directly with the religious concerns which plagued Endo's entire life. The novel centers on Rodrigues, a young Jesuit evangelist who travels to 17th-century Japan from Portugal in order to discover why his mentor has apostatised rather than suffer martyrdom.

Soon after his arrival the young missionary is himself captured and forced to witness the brutal torture of native Japanese converts, a process that will only cease if Rodrigues is prepared to trample on the image of Christ. Although he prepares himself for martyrdom, Rodrigues eventually capitulates and desecrates the image of Christ having decided that, in this instance, martyrdom would be unacceptably selfish.

The 11 stories in Endo's collection Stained Glass Elegies (1984) further explore the conundrum of Catholic faith, as the author presents us with a series of characters whose beliefs are fading and who cling precariously to inherited practices which can be easily stripped from them. Endo's "moral weaklings" continually restage the problematic encounter between Japanese and western understandings of self and God, an encounter which, as Endo's work develops, comes to be increasingly characterised by an ongoing interrogation of the word "betrayal".

By the time Endo reached the second half of his career it was clear that the defining theme of his oeuvre was the yawning chasm between the internal contradictions and pressures of Japanese life on the one hand, and the world of Christianity and Europe on the other.

How can one be both Japanese and western? How can one be a Christian and Japanese? Faced with two seemingly essentialist and inflexible ideologies, Endo sought to synthesise where it appeared there was neither room nor possibility for fusion. Not only did Japanese society appear "closed" and resistant to change, Christianity - in the form of Catholicism - appeared to him to be equally stubborn and insular.

Endo worried that Christianity might well be ill-suited to the temperament of Japanese religious psychology, which he felt demanded a more forgiving and accommodating God than the image of God that was being propagated by the Catholic church. In these circumstances Endo's task became clear to him. He would attempt to retailor Christianity into a suit of clothes that could sit comfortably upon the Japanese body. But, as he was endeavouring to do this, he would also be wrestling the face of Japanese society around and pointing it towards a mirror where it would have no choice but to stare at its own hypocrisies.

I ask Mr Kato if I am right in thinking that the recurring image of the swamp in Endo's work implies that Endo believed Japan to be a swamp, or a sea of mud, in which it was impossible to plant Christianity and expect it to take root. He nods, but is quick to clarify the situation.

"Your European God", he says, "is male. A father who is hard and who likes to punish, but we Japanese prefer a female image of God who is warm-hearted and forgiving." Mr Kato thinks for a moment, and then he continues. "However, towards the end of his life Endo did come to believe that there was only one God, that male or female it was the same person, and this is what we see in his final novel Deep River [1994] when the Japanese tourists travel to India and find their spiritual selves."

I am slightly taken aback and suggest to Mr Kato that this must mean there was some kind of a shift in position by Endo, perhaps even an abandonment of his self-stated quest to retailor Christianity for the Japanese.

"Perhaps," begins Mr Kato, "Japanese people have begun to travel outside of the country now, and, as in the novel Deep River, their own encounters with life beyond this country are changing both them and this society. They are doing some of the retailoring for themselves now." Mr Kato falls silent.

I look at him and want to be sure that I understand. I ask him if he is saying that by the end of his life Endo had moved beyond his early attempts to marry the essentialist notion of Japanese identity, to the essentialist notion of Catholic identity? Mr Kato drains his cup of coffee and then he stares into the middle distance. "Yes," he says. And then he turns and looks at me. "Endo witnessed many changes and developments in modern Japanese society."

Today there is an Endo Museum in Nagasaki, the Japanese city that has the most profound connections with the west. Here one can discover Endo's papers, manuscripts, letters, books, pens, even his clothes, all housed in a building that faces west. In Japan Shusaku Endo is remembered as a deeply-respected author who wished to bring about a coming together of Japanese manners with European ideas, but he has his critics. Soon after the opening of the museum in 1999, a memorial plate that had been established to commemorate the novel Silence was defaced with paint by Japanese Catholics who objected to the fact that Rodrigues chose to step willingly on the image of Christ.

During Endo's lifetime, Catholic groups successfully lobbied to block his being awarded the Nobel Prize for literature, but since his death in 1996 a new generation of Japanese Catholic writers has emerged and, despite the controversies, Endo's influence remains considerable. In fact, Mr Kato is at pains to assure me that Japanese readers consider Endo to be one of the handful of great 20th-century Japanese writers. "Endo" he says, "created space for change in our society. He is a bridge from the old to the new."

Mr Kato and I fall quiet. Out of the corner of my eye I can see the waitress hovering expectantly, and I think about ordering another cup of coffee. And then it suddenly occurs to me. I regarded the Britain that I grew up in during the 60s and 70s as inflexible and not readily open to change. Listening to people telling me to "go back to where you come from" suggested to me that I was, of course, the unwelcome evidence of change. How would I ever reconcile my world, my people, myself, to a Britain that had a woefully narrow idea of national identity?

My life has been peppered with betrayals, both small and large, both personal and national, and by the time I was ready to leave university I knew that attempting to make contemporary British society accepting of, and even comfortable with, the complexities of her past and present would be a large part of my life's work. In fact, as I decide to order yet another cup of coffee I realise that the inflexible rigidity of the Japanese society that Endo portrays does, in fact, strike a familiar chord in me.

The waitress places two more cups of coffee before us. I will soon be able to repair the awkward silence between Mr Kato and myself, and give him an answer to his question, for I now understand that it is "Endo's people" who provide me with conclusive evidence of a connection between Endo's world and my own. Dr Suguro, the man caught up in the vivisection scandal, reminds me of a young 19th-century English woman who finds herself on her father's Caribbean plantation "supporting" a system that she gradually comes to understand is "unsupportable".

"Endo's people" remind me of the slave ship captain who slowly realises that the trading intercourse that he is perpetuating is actually immoral. They remind me of the African man who sells his own children into slavery, or the racist little Englander, angry because he doesn't understand why and how his society is changing.

"Weak" people caught up in historically conditioned moral situations in somnambulant societies that are reluctantly waking up to change. I may not share Endo's Catholicism, nor his difficult internal debate with the nature of his faith, but his social and moral vision, and the manner in which he has sought to turn his understanding of inflexible societies and ideologies into literature, has been an important influence upon me.

Mr Kato smiles. Having listened to my long-winded answer to his question, Mr Kato seems pleased now to "understand" why Endo means so much to a writer from the other side of the world. However, as the bill arrives, Mr Kato is concerned to stress that despite the gravity of his subject matter, Endo was very humourous and he remained an optimist.

From the little that I had read about Endo's life, I had already guessed as much. I reassure Mr Kato that to my mind Endo's great gift to his readers, Japanese or otherwise, is to dignify ambiguity. To celebrate the puzzling grey area, and remind us that those old loyalties and certainties are, in our modern world, subject to fluidity and transformation irrespective of what the authorities above us - religious or otherwise - might have us believe.

And today, if we are to survive our 21st-century world, slippage, hybridity and change must be embraced and go unpunished. Endo's baptism, and his journey to France, rocked the foundation of his identity. The fact that he chose not fearfully to grasp a "safe", reductive, and uncomplicated identity, and he chose instead to try and synthesise these new influences and shape a new form of Japanese identity for himself and his society, is his great achievement. Mr Muneya Kato stands and gives me a small bow, which I - somewhat self-consciously - return in kind.

He clears his throat.

"Before Endo writes any book he always picks up Mr Graham Greene's The End of the Affair and reads it through. I think maybe you should know this." I thank Mr Kato for his time and smile. Again there is more bowing, and then I watch him thread his way through the crowded foyer of the hotel and disappear through the glass doors and out into the busy streets of the Shibuya shopping area. What I didn't tell Mr Kato is that before I write any book I always pick up the work of Mr Shusaku Endo - usually the novel Silence. This literary baton-passing continues to make some highly unlikely teams out of a rainbow coalition of writers.